Acanthoplus discoidalis

Acanthoplus discoidalis

''Acanthoplus discoidalis'' is a species of katydid that is native to Namibia, Botswana, and South Africa Zimbabwe. They are wide-bodied, flightless and can grow to around 5&nbsp;cm. Their thorax is covered in sharp spines and they have a pair of strong biting jaws. They are able to defend themselves against predators in an unusual manner by squirting haemolymph out of their bodies....hieroglyph snipped... Their populations peak in autumn and their bodies often litter roads during this time. When deprived of protein and salt they can become cannibalistic.

Reproduction

''Acanthoplus discoidalis'' have a relatively long courtship period, it starts at sunset and is usually completed by sunrise. Males stridulate which attracts females to their location. Males produce a large sperm pouch and an associated spermatophylax - together termed the spermatophore. They therefore cannot mate again for some time as they have to wait until a new spermatophore has grown. Females mate once before laying eggs, and then mate and lay eggs in a random order. This means that it is advantageous for males to mate with virgins over non-virgins as a higher proportion of the offspring will be their own. Males are able to discriminate between virgins and non-virgins and successfully complete more matings with virgins and they transfer their spermatophore more quickly when mating with virgins. Virgins are lighter than non-virgins allowing males to distinguish between virgins and non-virgins by determining the mass of the female when they copulate.

Food

''Acanthoplus discoidalis'' are omnivorous and will eat many different foods. One record documented them attacking Red-billed Quelea nestlings. It is believed that they may be able to detect the location of nests using auditory signals.

Defense

''Acanthoplus discoidalis'' have several defensive mechanisms that they use when attacked, as well as the innate defence provided by their armoured exoskeleton. The mechanism used depends on the sex of the individual and the method of attack. When attacked from the side, males will stridulate and both sexes will attempt to bite the attacker. In around 50% of attacks from the side, both sexes will autohaemorrhage, squirting between 5&nbsp;mg and 80&nbsp;mg of toxic haemolymph at their attacker over distances up to 30&nbsp;mm. When attacked from above and therefore less able to bite their attacker they autohaemorrhage more than when attacked from the side. Experiments have shown that the haemolymph is distasteful to at least two reptile species, but the compounds that confer this are unknown. It has been hypothesised that they may be phytotoxins found in plants that the crickets eat and that they then sequester these to use as defensive compounds themselves. After autohaemorrhaging they clean themselves meticulously, this is thought to be done so that other members of the species do not cannibalise them. Bateman and Fleming, experts on the species, believe that autohaemorrhage is a carefully regulated defence response rather than an accidental consequence of being attacked. Another defensive response is to regurgitate their stomach contents when attacked, this is used more often when the insect has already been attacked repeatedly.